Plantronics CS70N echo issues are not something that we typically get calls about, but most wireless headsets can certainly have some echo. There are a couple of different scenarios and instances that can make the Plantronics CS70N have an echo problem.
Compatibility: Although the Plantronics CS70N is pretty universal and compatible with most phones, there are a couple of makes and models that they do not work properly with, such as AT&T three digit model number phones and a most GE phones. For whatever the reason, these specific phones can make Plantronics headsets buzz and do quirky things so that they do not function properly. AT&T four digit model phones work just fine.
Connectivity: The Plantronics CS70N can echo and not function properly if it is not hooked up correctly. The Plantronics wireless headsets such as the CS70N are designed to plug into the handset receiver jack on the telephone base. You simply unplug your handset receiver’s coiled cable from the handset jack on the telephone and plug the wireless CS70N base into the handset jack, then you plug your handset receiver into the designated jack on the wireless headset base. That way you can still use your phone like normal if you want to. Some phones do have a dedicated headset jack, but that is used for a corded headset with a phone model specific cable, not the Plantronics CS70N. So just make sure that the wireless headset base is plugged in-line between the handset receiver and the base of the phone and not a headset jack. (* This does not pertain to Cisco 7940, 7960, & 7970 series phones… They are different *)
Settings: The configuration and settings on the Plantronics CS70N must be adjusted correctly otherwise it can make the headset echo. One of the most common reasons for the Plantronics CS70N to echo is a volume level being too loud, typically it’s the microphone volume. The master control for the mic volume on the very bottom of the CS70N base should usually be on setting “B”, and then you should use the mic volume quick adjustment buttons (plus & minus) on the upper back of the base unit to fine tune your speaking volume. And as far as your listening volume, it is the 1 – 4 switch on the lower back of the CS70N base. Number 1 is the loudest, adjust accordingly. The other configuration that can make the Plantronics CS70N echo is the compatibility setting dial on the left side of the base. It is the dial that looks like you can use a flathead screwdriver or a dime to adjust it, and it is numbered 1 – 4. Typically for most phones, number 1 should be in the 3 o’clock position, which would also be lined up with the little ridged area to the right of the dial. This is very important because it changes the internal compatibility of the unit, even if it’s off a little, it makes a world of difference. It has to be right on mark, otherwise it can make a wireless headset echo and do other quirky things as well.
If the Plantronics CS70N is hooked up properly, the volume levels are set correctly and the compatibility dial is where it needs to be, see the Plantronics CS70N page on our website for instructions on how to do a system “reset”, under the “Additional Information” tab.